Pressure atomization burners of the above-described type are operated according to the state of the art at one output stage, wherein the mean heat output can be varied by varying the on time. For heating up rapidly, it is necessary to design the device for a high burner output. However, only small amounts of energy are needed to keep the device warm. However, if the on time is shorter than the minimum combustion time, trouble-free operation of the burner is no longer possible. The consequence of this is combustion generating large amounts of pollutants with deposits in the flame tube or in the heater. Pressure atomization burners operated with a one-stage output for vehicle parking heaters have been known, e.g., from DE 195 34 866 A1 or DE 35 36 143 C2. If the burner is to be operated at another output, the atomization nozzle and the drive motor are replaced with correspondingly different units.